I live alone. I have friends and people over but as soon as they leave I start to feel alone. Its a form of depression. There are a lot of things we can do to fill our day, its just a matter of wanting to. Find a way to motivate yourself like making a list or just writing how you feel. The more I write the deeper I search within myself and talk myself into taking action. Find what works for you.
I comment a lot on other peoples posts here. Thats a great way to help them, help you , and meet new great people.

What would u say to someone who says to u, "I am so lonely I don't know what to do"? You there u have it. You just got your answer. You already know what to do. You just have to step up to the plate and do it.

andriavic what do you mean by saying you should allready know what to do?

reply #4, Everybody "already" has their own answers when it comes to things like this.

sorry you are feeling that way, personally facebook i think was never inteded for the lonley, it is a social comparison website, we people post how many "freinds ? " they have and how much fun they are having that really trying to connect to people.
Andrea has a point, i know you are young, so its prossible that you havent developed coping stratergies for dealing with being alone, but the answers you seek are within, asking others what to do, opens yourself up for all sorts of views some good some not so good.
try doing some google searches on loneliness there are some helpful websites out there that will give practical professional advice.